Pheromone-mediated Mating Disruption Research Articles

Mating disruption technology: An innovative tool for managing yellow stem borer (Scirpophaga incertulas Walker) of rice in Indonesia

Yellow stem borer (YSB) of rice, Scirpophaga incertulas Walker, causes significant damage to rice production in Indonesia. YSB management largely depends on insecticide applications and alternative management practices are very few and impractical. Pheromone-mediated mating disruption (MD) is a new way to manage YSB while reducing dependence on conventional insecticides. Pheron™ RSB is an low-density polyethylene (LDPE) MD dispenser, containing 1.25 g of a four-way blended insect sex pheromone components - Z11-Hexadecenal, Z9-Hexadecenal, Z13-Octadecenal, Z9-Octadecenal in a ratio of 75, 8.6, 9.4, and 7 respectively. The objective is to evaluate MD by Pheron™ RSB as a tool for season-long management of YSB. Dispensers were applied at a rate of 20 dispensers/ha in a minimum area of 4 ha. We conducted these trials at 74 locations, non-replicated, across Java, in the wet and dry seasons of 2020–2021 where YSB are endemic and problematic. Efficacy of MD in pheromone foundational practice (PFP) was compared to conventional grower practice (CGP). Trap reduction, a measure of MD was significantly higher (>70%) in PFP as compared to CGP. A major benefit of MD is reduction in damage. Significantly lower damage to rice tillers (40–46%) was seen in PFP compared to CGP. Lower damage in PFP likely protected yield by 0.43 to 0.76 ton/ha compared to CGP. Compared to PFP, CGP required 40–56% higher insecticide applications to manage YSB. Pheron™ RSB provided season-long MD and proved to be a powerful tool for integrated management of YSB.

Pheromone-mediated mating disruption of the European grain moth Nemapogon granellus in ham factories

Nemapogon granellus is a lepidopteran species that can cause significant damage to stored animal products such as meats, sausages and cheeses. In the warehouses where such products are stored, pheromone-based control approaches can avoid or reduce insecticide chemical treatments and be more effective than traditional control methods. This study aimed to evaluate the effectiveness of mating disruption (MD) techniques to control N. granellus populations in ham factories. Trials were conducted in two factories located in Northern Italy. In both locations two warehouses were selected: a warehouse test where dispensers, loaded with 10 mg of N. granellus pheromone, were deployed at a density ranging from 1 unit/22.5 m3 (factory A) to 1 unit/25 m3 (factory B), and a control warehouse left untreated. To assess the mating disruption efficacy, the reduction of the number of mated females in water traps, placed in control and treated warehouses, was used as main parameter. The results indicated a substantial reduction in mated females in the treated warehouses in comparison with control warehouses in both the sites of experiments. In detail, the total number of mated females sampled in water traps was above 90% in control warehouses, in warehouses treated with MD technique this percentage was below 50%. In addition, a “trap shutdown” effect was recorded in MD treated warehouses of both factories. These findings suggest that mating disruption is a promising technique that can be positively applied in the integrated pest management of N. granellus in ham factories.

Field tests of candidate pheromone blends show promise for mating disruption of the invasive swede midge (Diptera: Cecidomyiidae)

Abstract Swede midge, Contarinia nasturtii (Kieffer) (Diptera: Cecidomyiidae), causes severe economic losses in Brassica Linnaeus (Brassicaceae) crops in its invasive range in North America. Larvae feed within the meristem of their host plants, causing deformed heads, stems, and leaves. Pheromone-mediated mating disruption is particularly promising for swede midge management in high-value vegetable crops because its use is allowed in organic production. However, a major challenge to developing economically viable mating disruption is that the stereospecific three-component swede midge pheromone is costly to synthesise. In broccoli (Brassica oleracea Linnaeus var. italica) field plots, we tested whether stereospecific, lower-cost racemic, and single-component pheromone blends resulted in trap shutdown and reduced crop damage compared to nontreated controls. We found a significant reduction in males caught in three-component stereospecific and racemic pheromone–treated plots but not in the single-component treatments. Although marketable broccoli yields were not higher overall in the pheromone-treated plots compared with those in the controls, yields were significantly higher in the three-component stereospecific treatment in year 2. Therefore, the three-component stereospecific blend shows promise as a pheromone blend for swede midge mating disruption. However, due to high cost and levels of crop damage across all treatments, additional research is necessary to optimise swede midge mating disruption.

Trapping Soybean Looper (Lepidoptera: Noctuidae) in the Southeastern USA and Implications for Pheromone-Based Research and Management

Novel strategies for the management of soybean looper, Chrysodeixis includens (Walker) (Lepidoptera: Noctuidae), are needed due to its increasing importance, costs, and challenges of management in soybeans (Glycine max [L.] Merr.; Fabaceae) in the Americas. Pheromone-mediated mating disruption may be 1 such novel strategy, but an effective tool for estimating mating disruption success must be found. The technique of trapping male moths using pheromone baited traps is a common method for assessing mating disruption technology. This paper reports on the testing of 2 trap types and 3 commercially available lures containing (Z)-7-dodecenyl acetate as the major active component. Trapping was conducted at 5 locations in the southern USA in the summer of 2019. Universal moth traps and delta traps were tested in combination with the Alpha Scents, Bio Pseudoplusia, and Scentry brand lures along with unbaited traps. Overall, both trap types were effective at capturing C. includens male moths, with universal traps having a higher capture rate. The Alpha Scents and Bio Pseudoplusia lures both had a significantly higher capture rate than the Scentry lure regardless of trap design. The active components of the Scentry lure differed from the others with the inclusion of 2 known minor pheromone components (esters) of C. includens, (Z)-7-dodecenyl propionate and (Z)-7-dodecenyl butyrate. The amount of (Z)-7-dodecenyl acetate of the Scentry lure also was lower than the Alpha Scents and Bio Pseudoplusia lures. The additional esters or unidentified components (impurities) of the Scentry lures may have influenced C. includens captures. A large number of Ctenoplusia oxygramma (Geyer) (Lepidoptera: Noctuidae) were captured in traps at 3 of the locations, though not in those traps baited with the ester-containing Scentry lure. Taken together, the data provide insight into effective trapping methods for C. includens and elucidates the need for researchers to understand the effectiveness of trapping components available in a region and the need for researchers to plan for captures of non-target species in pheromone-related research.

Areawide mating disruption for vine mealybug in California vineyards

The mealybug, Planococcus ficus (Signoret), is one of the more damaging vineyard pests and an important vector of Grapevine leafroll-associated viruses. Pheromone-mediated mating disruption is a commercially available and environmentally sustainable control tool for P. ficus. Here we report on a three-year areawide study of P. ficus mating disruption in Napa County, California, where pheromone dispensers were deployed across large (53–66 ha) multi-owner sites that were paired with sites that did not receive pheromone. Male P. ficus captures in pheromone traps were correlated with mealybug numbers and crop damage, and were useful in identifying ‘hotspots’ to be targeted with insecticide applications for areawide control. Trap catches at mating disruption sites were far lower than untreated sites, although mealybugs were still present at mating disruption sites. Evidence indicated that mating disruption reduced P. ficus density and spread, particularly in areas with low initial mealybug densities. In the third year, areawide mating disruption was discontinued at the former mating disruption sites and, as evidence of its impact, P. ficus trap captures increased. These results suggest that mating disruption and well-timed, effective insecticide applications play complementary roles, and that monitoring the areawide distribution of pests is a critical component of programs for controlling P. ficus.

Synthetic pheromone exposure increases calling and reduces subsequent mating in female Contarinia nasturtii (Diptera: Cecidomyiidae).

Pheromone-mediated mating disruption, which uses large amounts of synthetic female pheromones to interrupt insect reproductive behavior, has been successful for managing important agricultural pests. While multiple mechanisms have been discovered explaining how synthetic pheromone treatments prevent males from finding females, it is less clear how unnaturally large doses of synthetic sex pheromone impact the behavior of female insects, particularly nonlepidopteran females. In some species, 'autodetecting' females possess pheromone receptors and respond to ambient pheromones by altering their mating behavior. Here, we test whether exposure to stereospecific and racemic synthetic pheromones influences calling and subsequent propensity to mate in female swede midge (Contarinia nasturtii Kieffer; Diptera: Cecidomyiidae), a pest of Brassica crops. In both laboratory and field settings, females exposed to stereospecific and racemic three-component pheromone blends called significantly more frequently and for longer durations than midges in control treatments. In the field, midges were twice as likely to call in pheromone-treated plots versus nontreated plots. Additionally, pheromone pre-exposure reduced subsequent mating: while 68% of female midges mated following control conditions, only 42% and 35% of females pre-exposed to stereospecific and racemic three-component blends mated, respectively. While more frequent calling within pheromone-treated backgrounds may increase the likelihood that females are detected by males, a reduction in female propensity to mate would increase the efficacy of a pheromone-mediated mating disruption system. Our work presents the first known investigation of autodetection behavior in Cecidomyiidae. Additional research is necessary to understand the implications of female autodetection for swede midge management.

Sex Pheromone Aerosol Devices for Mating Disruption: Challenges for a Brighter Future

Pheromone-mediated mating disruption (MD) represents an important tool to manage insect pests in agriculture and forestry. MD relies on the release of synthetic sex pheromones from dispensers in crops, interfering with mate finding and reproduction of a pest through both competitive and non-competitive mechanisms. MD programs primarily rely upon “passive” dispensers, used at high densities per hectare (200–3000 units∙ha−1). In addition to the labor required for their application, another disadvantage of “passive” dispensers is the continuous release of pheromones, regardless of the time of day or the pest flight activity. Aerosol delivery systems can overcome the drawbacks of passive dispensers as they are applied at far lower density (2–5 units∙ha−1) and they can be programmed to release pheromones at selected time intervals when the target pest is active. However, the mode of action of aerosol dispensers is still not well understood and there are concerns of whether they are as effective as passive dispensers. This review focuses on the history of aerosol dispensers, mode of action, and effectiveness on various crops; deployment strategies; and the movement of pheromone once released. Limitations of aerosols and challenges for future research and commercial use are discussed.

Racemic Pheromone Blends Disrupt Mate Location in the Invasive Swede Midge, Contarinia nasturtii.

Swede midge, Contarinia nasturtii Kieffer, is an invasive cecidomyiid pest that causes serious losses of Brassica oilseed and vegetable crops in the Northeastern U.S. and Canada. Currently, few alternatives to systemic insecticides exist for its management. Because a single feeding larva can render heading Brassica crops unmarketable, management strategies that prevent oviposition are needed urgently. Pheromone-mediated mating disruption is a promising management approach for swede midge because it prevents mating and subsequent crop damage. While the swede midge pheromone has been identified, one of the major barriers to using it in mating disruption is the high cost of synthesis. Racemic blends, consisting of natural and non-natural stereoisomers, could be useful for mating disruption because they are cheaper to produce. However, it is not clear whether racemic pheromone blends attract males and/or prevent them from locating and mating with females. Here, we studied the behavior of male swede midge in Y-tube and wind tunnel bioassays to pheromone blends. Specifically, we tested whether males: (1) are attracted to different doses of pheromone, (2) discriminate between blends comprising natural stereospecific or racemic components, or a combination thereof, and (3) are able to locate and copulate with females in pheromone-permeated olfactometers. We found that picogram amounts of pheromone attracted males and prevented them from locating females in y-tube olfactometers. While males were more attracted to stereospecific blends, compared to racemic blends, all blends tested prevented nearly all males mating with females. Therefore, low dose racemic blends may be promising for pheromone-mediated mating disruption.

Managing the vine mealybug, Planococcus ficus, through pheromone-mediated mating disruption.

The vine mealybug (VMB), Planococcus ficus (Hemiptera: Pseudococcidae), is a key insect pest of vineyards. While pheromone-based mating disruption (MD) has been successfully tested against a wide range of insect pests, knowledge about its efficacy against key mealybug species, such as P. ficus, is scarce. In this study, a novel MD product, Isonet® PF, was evaluated by testing 300, 400, and 500 dispensers/ha at four study sites located in Northern (Veneto) and Southern (Sicily) Italy. Experiments were carried out over 2years by monitoring the mealybug populations in wine grape and table grape vineyards managed with and without the application of MD. Pheromone dispensers were periodically collected during the grapevine-growing season, extracted, and analyzed by GC-MS, to determine their pheromone content and the release in mg/ha/day. The results showed that use of the MD dispenser Isonet® PF reduced the percentage of VMB-infested bunches and the number of VMB specimens per bunch compared with the untreated controls. This was recorded over 2years at all experimental sites. Differences in the incidence of infested bunches among the three tested rates of Isonet® PF were not detected. Overall, the results presented here contribute to optimizing the sex pheromone dosage used in MD control programs against VMB allowing a reduction of broad-spectrum insecticides currently employed to manage this important pest.

Lobesia botrana males mainly fly at dusk: video camera-assisted pheromone traps and implications for mating disruption

Pheromone-mediated mating disruption (MD) is currently considered an effective strategy to control the European grapevine moth (EGVM), Lobesia botrana, with a successful interference on natural female calling during the male searching flight. However, little is known on the impact of the hour of the day on EGVM male flight. While various models forecasting the day of maximum presence of males per flight have been developed, field research on the male flight activity over 24 hours is scarce. Hence, we used video camera-assisted pheromone traps to allow a continuous monitoring of EGVM flights over daylight and night hours, quantifying captures of males. Experiments were carried out in three vineyards located in northern Spain over two years (2016 and 2017). Results showed that EGVM flight mainly occurred between 21:00 and 23:00 h (GMT+1, daylight saving time). Furthermore, male catches significantly differed over the study year, annual flight period and vineyard. Most of the dispensers used worldwide for EGVM MD continuously release the main sex pheromone component [(7E,9Z)-7,9-dodecadien-1-yl acetate], except for some automatic devices releasing puffs of sex pheromones at selected time intervals. The findings presented here can be useful to optimize the MD technique, identifying selected time intervals when the release of EGVM synthetic pheromones can be concentrated, boosting MD efficacy against this important pest, minimizing the release of synthetic sex pheromone molecules in the environment and reducing application costs.

Delay in Mating Reduces Reproductivity but Increases Life Span in Tobacco Cutworm, Spodoptera litura Fabricius (Lepidoptera: Noctuidae).

A pheromone-mediated mating disruption is a vital tool in the management of insect population dynamics that not only prevents mating but also delays mating in the target insect. Here, we examined the effect of delayed mating on the longevity and reproductive performance of the global pest, Spodoptera litura Fabricius (Lepidoptera: Noctuidae). Delayed mating was imposed on both sexes simultaneously, males only, and females only. The results showed that a 30-40% reduction in the successful mating rate of S. litura was caused by 7-d delay in mating. Increased mating ages of both sexes of S. litura resulted in a significant decrease in 3-d-old delayed mating, followed by an increase in mean duration of copulation. Furthermore, delayed mating had a significantly negative influence on the number of S. litura eggs produced. Mating delay imposed on both sexes simultaneously had a significantly greater effect on longevity and the number of eggs than when it was applied to either sex alone, and females were more severely affected by delayed mating than males in terms of longevity. Percentage of mating, fecundity, and female longevity were all significantly correlated with the number of days delayed mating. However, the hatching rate of eggs was not significantly affected by an increased delay in mating. Overall, our results indicated that delayed mating in both females and males drastically reduced the females' reproductive output, which itself was affected more by increasing the age at mating of females than males.

Eco-friendly pheromone dispensers-a green route to manage the European grapevine moth?

The development of environmentally sustainable control strategies to fight insect pests is a key challenge nowadays. Pheromone-mediated mating disruption (MD) is based on the release of synthetic sex attractants into a crop, interfering with mate finding of a given pest species. However, a limited number of research items have been published on the optimization of MD strategies against the European grapevine moth, Lobesia botrana, as well as on the use of biodegradable dispensers to reduce waste production in vineyards, despite the high economic importance of this pest. Therefore, the present study evaluated the efficacy of the MD products Isonet® L TT and the biodegradable Isonet® L TT BIO, applied at various densities, in reducing L. botrana damage on grapevine in comparison to an untreated control and the reference MD product Isonet® L. Experiments were conducted in three different areas of grapevine cultivation, located in Central and Northern Italy, over three different years. Our MD approach allowed a reliable control of the three generations of L. botrana during the whole grape growing season, leading to a significant reduction in the infested flower clusters andbunches, as well as in the number of nests per flower cluster and bunch, if compared to the untreated control. The performances of Isonet® L TT BIO, Isonet® LTT, and Isonet® L did not differ in terms of infested flower clusters/bunches, as well as nests per flower cluster/bunch. This was confirmed in all experimental sites over 3years of field experiments. Overall, the present research provides useful information for the optimization of MD programs against L. botrana, highlighting the interesting potential of biodegradable pheromone dispensers that can be easily applied at low densities in vineyards, reducing the use of chemical pesticides to control moth pests.

First Report of Mating Disruption With an Aggregation Pheromone: A Case Study With Tetropium fuscum (Coleoptera: Cerambycidae).

Tetropium fuscum (F.), native to Europe and established in Nova Scotia, Canada, since at least 1990, is considered a low-to-moderate threat to spruce (Picea spp.) forests in North America and regulated as a quarantine pest by the Canadian Food Inspection Agency. We tested broadcast applications of the aggregation pheromone racemic (5E)-6,10-dimethyl-5,9-undecadien-2-ol (fuscumol), formulated at 10% concentration in Hercon Bio-Flakes (Hercon International, Emigsville, PA), for efficacy in disrupting T. fuscum mating and suppressing populations. Two applications of 2.5-2.75 kg Bio-Flakes (250-275 g a.i.) per ha per season significantly reduced trap catches and mating success (2009, 2010, 2012): about 30% of females trapped in treated plots had mated compared with 60% of females trapped in untreated plots. Similar reductions in mating success were observed in 2011 with one or two 4.5 kg/ha applications of Bio-Flakes. Mean densities of T. fuscum colonizing sentinel bait logs or girdled trees were 36% lower in pheromone-treated plots than in untreated plots, but the difference was not statistically significant. Lack of population suppression may have been because mated females immigrated into treated plots or because populations were so high that despite a 50% reduction in mating success, absolute numbers of mated females were sufficient to infest our bait logs or trees. This is the first demonstration of insect mating disruption via broadcast application of an aggregation pheromone. Pheromone-mediated mating disruption has potential to slow the spread of invasive cerambycids by targeting low-density outlier populations near or beyond the leading edge of an infestation.

Pheromone-mediated mating disruption of Planococcus ficus (Hemiptera: Pseudococcidae) in Tunisian vineyards: Effect on insect population dynamics

AbstractThe mating disruption technique using Checkmate

Development of natural waxes dispensers for pheromones and use in mating disruption of the ambrosia beetle Megaplatypus mutatus in poplar (Populus spp) plantations

Megaplatypus mutatus (= Platypus mutatus) (Chapuis) is an ambrosia beetle native to South America that attacks live trees, mining deeply into the xylem through large tunnels. This activity weakens the structural integrity of the tree, causing severe stem-breakage and mortality. Attacks are initiated by pioneer males that select a host tree and build short nuptial galleries, to which they attract females using a sexual pheromone. Previously, we showed the potential for the strategy of pheromone-mediated mating disruption of M. mutatus in commercial poplar and hazelnut plantations in South America and Europe using polyethylene reservoir dispensers for pheromones. In the present work we replaced the polymeric reservoir dispensers by monolithic dispensers made by dispersion of the pheromone in natural waxes and the addition of kaolin and we found that: prior to pheromone deployment, the mean number of galleries per tree did not differ significantly between the control and treated plots and the same was observed after the mating disruption treatment for the control plot but not for treated plots, where the mean number of galleries were reduced. These findings confirm that mating disruption is a viable tool for management of M. mutatus in poplar plantations. Using natural wax dispensers has obvious advantages from an environmental point of view.

Monolithic dispensers for pheromones and their use in mating disruption of the ambrosia beetleMegaplatypus mutatusin poplar plantations

Megaplatypus mutatus (formerly Platypus mutatus) (Chapuis) is an ambrosia beetle native to South America that attacks standing live trees, mining deeply into the xylem through large tunnels. This activity weakens the structural integrity of the tree, causing severe stem-breakage and mortality. Attacks are initiated by pioneer males that select a host tree and build short nuptial galleries to which they attract females using a sex pheromone. Volatiles emitted are composed of (+)-6-methyl-5-hepten-2-ol [(+)-sulcatol], 6-methyl-5-hepten-2-one (sulcatone) and 3-pentanol. Previously, we showed the potential of the strategy of pheromone-mediated mating disruption of M. mutatus in commercial poplar and hazelnut plantations in South America and Europe using polyethylene reservoir dispensers for pheromones and found that damage reduction was greater than 56% in all cases. In the present study, the polymeric reservoir dispensers were replaced by matrix dispensers made by dispersion of the pheromone in natural waxes or polyethylene glycols that act as a matrix with the addition of a filler. After treatment, the number of mating galleries was significantly higher (70%) in control than in treated areas. Using natural materials for dispensers, we confirmed that mating disruption is a viable tool for the management of M. mutatus in poplar plantations.

Challenges of Mating Disruption Using Aerosol-Emitting Pheromone Puffers in Red Clover Seed Production Fields to Control Coleophora deauratella (Lepidoptera: Coleophoridae).

Sex pheromone-mediated mating disruption using pheromone puffer dispensers was evaluated to control Coleophora deauratella (Lepidoptera: Coleophoridae) at three red clover seed production fields in Alberta, Canada. The objectives of the study were to determine aspects of the biology of C. deauratella which may affect successful mating disruption, evaluate the ability of aerosol-emitting pheromone puffers to reduce male moth catch in small-plot trials, and evaluate the ability of puffers to reduce male capture in traps, larval numbers and damage in large-plot trials. The median longevity of male and female C. deauratella was 6 d in the laboratory where males emerged in larger numbers earlier than females (protandry). Male response to pheromone peaked at sunrise; thus, puffers were programmed to dispense pheromone throughout this time period. Small-plot (0.25 ha) mating disruption trials indicated that pheromone released from puffers could reduce male C. deauratella orientation to traps by 60.7 ± 18.6% compared with that in untreated control plots. Reduction of male orientation to traps in large-plot (5 ha) trials over the course of the season was also successful (93.7 ± 1.6%). However, there was no corresponding decrease in larval numbers or increase in seed yield in pheromone-treated plots. Challenges of mating disruption of C. deauratella appear to be immigration of mated females combined with high population densities.

Mating disruption of Coleophora deauratella (Lepidoptera: Coleophoridae) using laminate flakes in red clover seed production fields.

The red clover casebearer, Coleophora deauratella, is a significant pest in red clover (Trifolium pratense) seed production regions throughout the world. The internal feeding nature of C. deauratella larvae makes infestations difficult to control with insecticide. We test the ability of Hercon Disrupt Micro-Flakes(®) releasing the complete pheromone blend of C. deauratella to disrupt communication and mating in red clover seed production fields. Initial small-plot (0.25 ha) trials found a significant reduction (93.6 ± 2.9%) of male C. deauratella captured in pheromone-treated plots compared with untreated controls. Subsequent large-plot (5 ha) mating disruption trials found a significant reduction (72.3 ± 5.7%) in male C. deauratella captured in pheromone-treated plots compared with untreated control plots over the growing season. Furthermore, larval numbers were significantly reduced and seed yield was increased in pheromone-treated plots compared with untreated control plots. In a concurrent small-plot (0.0625 ha) trial with various flake densities, disruption increased with pheromone flake density, and the resulting graphical disruption profiles matched the theoretical predictions of mating disruption by competitive attraction. Pheromone-mediated mating disruption with laminate flakes has the potential to suppress C. deauratella populations and may help to reduce damage even at high pest densities. © 2014 Society of Chemical Industry.

Efficacy and mechanisms of communication disruption of the red clover casebearer moth (Coleophora deauratella) with complete and partial pheromone formulations.

The red clover casebearer, Coleophora deauratella Leinig and Zeller (Lepidoptera: Coleophoridae), is a major pest of red clover (Trifolium pratense L.) grown for seed in Canada and parts of Europe. Insecticides are ineffective against C. deauratella, and other control methods, such as pheromone-mediated mating disruption, need to be explored. The efficacy and mechanisms of communication disruption were evaluated in small-plot trials (0.25 ha) with reservoir-type rope dispensers loaded with either the complete pheromone blend [10:1 ratio of (Z)-7-dodecenyl acetate: (Z)-5-dodecenyl acetate] or the major component alone [(Z)-7-dodecenyl acetate]. Both formulations reduced catches of male C. deauratella in pheromone traps (>99.6 %). In pheromone-treated plots, more males were caught on yellow sticky cards near dispensers that released the complete pheromone blend, than on cards near dispensers releasing the major component. In the laboratory, after pre-exposure to either the complete blend or the major component for 1 h, male C. deauratella antennae became adapted, as measured by electroantennograms conducted 5 min. after treatment. Adaptation due to pre-exposure to either formulation resulted in a shift in the pheromone response threshold; antennae from pre-exposed moths responded more strongly to high pheromone dosages (5-50 μg) than did antennae from untreated control moths. Antennae from moths held in clean air for 24 h after pre-exposure recovered and responded similarly to pheromone as antennae from control moths. These results suggest that both formulations have the potential to disrupt pheromone communication in C. Deauratella, but that the disruption mechanisms of the two formulations likely differ.

Sex-Pheromone-Mediated Mating Disruption Technology for the Oriental Fruit Moth,Grapholita molesta(Busck) (Lepidoptera: Tortricidae): Overview and Prospects

A great deal of progress has been made over the last three decades in research on pheromone-mediated mating disruption technology for the oriental fruit moth,Grapholita molesta(Busck). Pheromones can interrupt normal orientation, and the most likely mechanism of pheromone disruption, competitive-attraction (false-plume following), invokes competition between point sources of pheromone formulation and females for males. This technology, performed by broadcasting pheromones into orchards to disrupt mate finding, has been successfully implemented in oriental fruit moth control. Reservoir-style dispensers made of polyethylene tubes, which release pheromone throughout the full growing season, are the current industry standard. Although reasonably effective, they require labor-intensive hand application. Recently, a new formulation, paraffin wax, which maximizes competition between point sources of synthetic pheromone and feral females for males, was shown to have high disruption performance. As this formulation is highly effective, inexpensive, and easy to produce, further study and development are advisable. Increased understanding of the principles of mating disruption will aid in the design of more effective dispensers. Continued research is needed to meet grower concerns with regard to risk, efficacy, and cost and to identify other semiochemicals that can be applied to this delivery system. Greater knowledge of the integration of different biological control methods is therefore essential.